Multiple virtual network interface support for virtual execution elements

ABSTRACT

Techniques are described for creating multiple virtual network interfaces usable by a logically-related group of one or more containers (“pod”) for communicating on respective virtual networks of a network infrastructure. In some examples, a control flow for pod network interface configuration on a host includes obtaining, by a CNI instance, a list of multiple virtual network interfaces from an agent of a network controller that is executing on the host. The single CNI instance processes the list of multiple virtual network interfaces to create corresponding virtual network interfaces for the pod and, for each of the virtual network interfaces, to attach the virtual network interface to the pod and to the virtual router or bridge for the host. In this way, the single CNI enables packetized communications by containers of the pod over multiple networks using the multiple virtual network interfaces configured for the pod.

TECHNICAL FIELD

The disclosure relates to a virtualized computing infrastructure and,more specifically, to configuring network connectivity for virtualexecution elements (e.g., virtual machines or containers) deployed tovirtualized computing infrastructure within a network.

BACKGROUND

In a typical cloud data center environment, there is a large collectionof interconnected servers that provide computing and/or storage capacityto run various applications. For example, a data center may comprise afacility that hosts applications and services for subscribers, i.e.,customers of data center. The data center may, for example, host all ofthe infrastructure equipment, such as networking and storage systems,redundant power supplies, and environmental controls. In a typical datacenter, clusters of storage systems and application servers areinterconnected via high-speed switch fabric provided by one or moretiers of physical network switches and routers. More sophisticated datacenters provide infrastructure spread throughout the world withsubscriber support equipment located in various physical hostingfacilities.

Virtualized data centers are becoming a core foundation of the moderninformation technology (IT) infrastructure. In particular, modern datacenters have extensively utilized virtualized environments in whichvirtual hosts, also referred to herein as virtual execution elements,such virtual machines or containers, are deployed and executed on anunderlying compute platform of physical computing devices.

Virtualization within a data center can provide several advantages. Oneadvantage is that virtualization can provide significant improvements toefficiency. As the underlying physical computing devices (i.e., servers)have become increasingly powerful with the advent of multicoremicroprocessor architectures with a large number of cores per physicalCPU, virtualization becomes easier and more efficient. A secondadvantage is that virtualization provides significant control over thecomputing infrastructure. As physical computing resources becomefungible resources, such as in a cloud-based computing environment,provisioning and management of the computing infrastructure becomeseasier. Thus, enterprise IT staff often prefer virtualized computeclusters in data centers for their management advantages in addition tothe efficiency and increased return on investment (ROI) thatvirtualization provides.

Containerization is a virtualization scheme based on operationsystem-level virtualization. Containers are light-weight and portableexecution elements for applications that are isolated from one anotherand from the host. Because containers are not tightly-coupled to thehost hardware computing environment, an application can be tied to acontainer image and executed as a single light-weight package on anyhost or virtual host that supports the underlying containerarchitecture. As such, containers address the problem of how to makesoftware work in different computing environments. Containers offer thepromise of running consistently from one computing environment toanother, virtual or physical.

With containers' inherently lightweight nature, a single host can oftensupport many more container instances than traditional virtual machines(VMs). Often short-lived, containers can be created and moved moreefficiently than VMs, and they can also be managed as groups oflogically-related elements (sometimes referred to as “pods” for someorchestration platforms, e.g., Kubernetes). These containercharacteristics impact the requirements for container networkingsolutions: the network should be agile and scalable. VMs, containers,and bare metal servers may need to coexist in the same computingenvironment, with communication enabled among the diverse deployments ofapplications. The container network should also be agnostic to work withthe multiple types of orchestration platforms that are used to deploycontainerized applications.

A computing infrastructure that manages deployment and infrastructurefor application execution may involve two main roles: (1) orchestrationfor automating deployment, scaling, and operations of applicationsacross clusters of hosts and providing computing infrastructure, whichmay include container-centric computing infrastructure; and (2) networkmanagement for creating virtual networks in the network infrastructureto enable packetized communication among applications running on virtualexecution environments, such as containers or VMs, as well as amongapplications running on legacy (e.g., physical) environments.Software-defined networking contributes to network management.

SUMMARY

In general, techniques are described for creating multiple virtualnetwork interfaces usable by a logically-related group of one or morecontainers (“pod”) for communicating on respective virtual networks of anetwork infrastructure. A container networking interface plugin (CGI) isa networking solution for application containers and is a runtimeexecutable that configures a network interface into a container networknamespace and configures the computing device (“host”) hosting thecontainer, which may be a member of a pod. The CNI further assigns thenetwork address (e.g., IP address) to the network interface and may alsoadd routes relevant for the interface, such as routes for the defaultgateway and one or more nameservers.

As described herein, in some examples, a control flow for pod networkinterface configuration on a host includes obtaining, by a single CNIinstance, a list of multiple virtual network interfaces from an agent ofa network controller that is executing on the host. The single CNIinstance processes the list of multiple virtual network interfaces tocreate corresponding virtual network interfaces for the pod and, foreach of the virtual network interfaces, to attach the virtual networkinterface to the pod and to the virtual router or bridge for the host.In this way, the single CNI enables packetized communications bycontainers of the pod over multiple networks using the multiple virtualnetwork interfaces configured for the pod.

The techniques may provide one or more technical advantages. Forexample, the techniques described herein enable configuration ofmultiple virtual network interfaces for a pod using a single CNI, whichmay reduce communication and resource overhead inherent with invoking aseparate CNI for configuring each virtual network interface. Thetechniques may also reduce a need to rely on a separate CNI broker thatmanages the invocation of separate CNI instances to create correspondingvirtual network interfaces for a pod. Whereas previous methods ofcreating multiple virtual network interfaces require separate CNIs(e.g., for calico, flannel, and SR-IOV), the techniques may enablesingle CNI instance described herein to handle configuration of each ofthe multiple virtual network interfaces for a pod. As another example,because CNIs are typically developed for use with a single type ofnetwork infrastructure, the CNI and the agent of the orchestrationsystem are separate processes. The techniques may reduce the number ofinter-process communications (IVCs) between the agent and a CNI instanceto configure multiple virtual networks interfaces for multiple virtualnetworks. In addition, or alternatively, by offloading aspects ofnetwork configuration for multiple virtual networks from theorchestration system to the CNI, the techniques may improve theversatility of the CNI to work with multiple different types oforchestration systems and network infrastructures,

In one example, a computing device comprises processing circuitrycoupled to a memory device; a network module configured for execution bythe processing circuitry; an orchestration agent configured forexecution by the processing circuitry, wherein the orchestration agentis an agent of an orchestrator for a computing infrastructure thatincludes the computing device, wherein the orchestration agent isconfigured to: instantiate a virtual execution element; and invoke thenetwork module, wherein the network module is configured to: obtain anidentifier of a first virtual network interface for a first virtualnetwork and an identifier of second virtual network interface for asecond virtual network; and attach the first virtual network interfaceto the virtual execution element to enable packetized communications bythe virtual execution element on the first virtual network; and attachthe second virtual network interface to the virtual execution element toenable packetized communications by the virtual execution element on thesecond virtual network.

In another example, a controller comprises one or more computing devicesinterconnected by a physical network, wherein each of the computingdevices comprises processing circuitry coupled to a memory device,wherein the controller further comprises: an orchestrator for avirtualized computing infrastructure, wherein the orchestrator isconfigured for execution by the processing circuitry, wherein theorchestrator is configured to: send, to a network controller, a requestto create, for a virtual execution element to be instantiated in acomputing device of the virtualized computing infrastructure, respectivevirtual network interfaces for a first virtual network and a secondvirtual network; and the network controller, wherein the networkcontroller is configured for execution by the processing circuitry,wherein the network controller is configured to: send, to the computingdevice, interface configuration data to configure a first virtualnetwork interface for the first virtual network and a second virtualnetwork interface for the second virtual network, wherein the interfaceconfiguration data includes an identifier of the first virtual networkinterface for the first virtual network and an identifier of the secondvirtual network interface for the second virtual network.

In another example, a method comprises sending, by an orchestrator for avirtualized computing infrastructure to a network controller for thevirtualized computing infrastructure, a request to create, for a virtualexecution element to be instantiated in a computing device of thevirtualized computing infrastructure, respective virtual networkinterfaces for a first virtual network and a second virtual network; andsending, by the network controller to the computing device, interfaceconfiguration data to configure a first virtual network interface forthe first virtual network and a second virtual network interface for thesecond virtual network, wherein the interface configuration dataincludes an identifier of the first virtual network interface for thefirst virtual network and an identifier of the second virtual networkinterface for the second virtual network.

The details of one or more embodiments of this disclosure are set forthin the accompanying drawings and the description below. Other features,objects, and advantages will be apparent from the description anddrawings, and from the claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating an example computinginfrastructure in which examples of the techniques described herein maybe implemented.

FIG. 2 is a block diagram of an example computing device that includes anetwork module for configuring multiple virtual network interfaces for aset of one or more virtual execution elements that share at least onevirtual network interface, according to techniques described in thisdisclosure.

FIG. 3 is a block diagram of an example computing device operating as aninstance of controller for a virtualized computing infrastructure,according to techniques described in this disclosure.

FIG. 4 is a flow diagram illustrating the example creation of multiplenetwork virtual interfaces for a virtual execution element using asingle network module, according to techniques described in thisdisclosure.

Like reference characters denote like elements throughout e descriptionand figures.

DETAILED DESCRIPTION

FIG. 1 is a block diagram illustrating an example computinginfrastructure 8 in which examples of the techniques described hereinmay be implemented. In general, data center 10 provides an operatingenvironment for applications and services for a customer sites 11(illustrated as “customers 11”) having one or more customer networkscoupled to the data center by service provider network 7. Data center 10may, for example, host infrastructure equipment, such as networking andstorage systems, redundant power supplies, and environmental controls.Service provider network 7 is coupled to public network 15, which mayrepresent one or more networks administered by other providers, and maythus form part of a large-scale public network infrastructure, e.g., theInternet. Public network 15 may represent, for instance, a local areanetwork (LAN), a wide area network (WAN), the Internet, a virtual LAN(VLAN), an enterprise LAN, a layer 3 virtual private network (VPN), anInternet Protocol (IP) intranet operated by the service provider thatoperates service provider network 7, an enterprise IP network, or somecombination thereof.

Although customer sites 11 and public network 15 are illustrated anddescribed primarily as edge networks of service provider network 7, insome examples, one or more of customer sites 11 and public network 15may be tenant networks within data center 10 or another data center. Forexample, data center 10 may host multiple tenants (customers) eachassociated with one or more virtual private networks (VPNs), each ofwhich may implement one of customer sites 11.

Service provider network 7 offers packet-based connectivity to attachedcustomer sites 11, data center 10, and public network 15. Serviceprovider network 7 may represent a network that is owned and operated bya service provider to interconnect a plurality of networks. Serviceprovider network 7 may implement Multi-Protocol Label Switching (MPLS)forwarding and in such instances may be referred to as an MPLS networkor MPLS backbone. In some instances, service provider network 7represents a plurality of interconnected autonomous systems, such as theInternet, that offers services from one or more service providers.

In some examples, data center 10 may represent one of manygeographically distributed network data centers. As illustrated in theexample of FIG. 1, data center 10 may be a facility that providesnetwork services for customers. A customer of the service provider maybe a collective entity such as enterprises and governments orindividuals. For example, a network data center may host web servicesfor several enterprises and end users. Other exemplary services mayinclude data storage, virtual private networks, traffic engineering,file service, data mining, scientific- or super-computing, and so on.Although illustrated as a separate edge network of service providernetwork 7, elements of data center 10 such as one or more physicalnetwork functions (PNFs) or virtualized network functions (VNFs) may beincluded within the service provider network 7 core.

In this example, data center 10 includes storage and/or compute serversinterconnected via switch fabric 14 provided by one or more tiers ofphysical network switches and routers, with servers 12A--12X (herein,“servers 12”) depicted as coupled to top-of-rack switches 16A-16N.Servers 12 are computing devices and may also be referred to herein as“hosts” or “host devices.” Although only server 12A coupled to TORswitch 16A is shown in detail in FIG. 1, data center 10 may include manyadditional servers coupled to other TOR switches 16 of the data center10.

Switch fabric 14 in the illustrated example includes interconnectedtop-of-rack (TOR) (or other “leaf”) switches 16A-16N (collectively,“TOR. switches 16”) coupled to a distribution layer of chassis (or“spine” or “core”) switches 18A-18M (collectively, “chassis switches18”), Although not shown, data center 10 may also include, for example,one or more non-edge switches, routers, hubs, gateways, security devicessuch as firewalls, intrusion detection, and/or intrusion preventiondevices, servers, computer terminals, laptops, printers, databases,wireless mobile devices such as cellular phones or personal digitalassistants, wireless access points, bridges, cable modems, applicationaccelerators, or other network devices. Data center 10 may also includeone or more physical network functions (PNFs) such as physicalfirewalls, load balancers, routers, route reflectors, broadband networkgateways (BNGs), Evolved Packet Cores or other cellular networkelements, and other PNFs.

In this example, TOR switches 16 and chassis switches 18 provide servers12 with redundant (multi-homed) connectivity to IP fabric 20 and serviceprovider network 7, Chassis switches 18 aggregate traffic flows andprovides connectivity between TOR switches 16. TOR switches 16 may benetwork devices that provide layer 2 (MAC) and/or layer 3 (e.g., IP)routing and/or switching functionality. TOR switches 16 and chassisswitches 18 may each include one or more processors and a memory and canexecute one or more software processes. Chassis switches 18 are coupledto 1P fabric 20, which may perform layer 3 routing to route networktraffic between data center 10 and customer sites 11 by service providernetwork 7. The switching architecture of data center 10 is merely anexample. Other switching architectures may have more or fewer switchinglayers, for instance.

The term “packet flow,” “traffic flow,” or simply “flow” refers to a setof packets originating from a particular source device or endpoint andsent to a particular destination device or endpoint. A single flow ofpackets may be identified by the 5-tuple: <source network address,destination network address, source port, destination port, protocol>,for example. This 5-tuple generally identifies a packet flow to which areceived packet corresponds. An n-tuple refers to any n items drawn fromthe 5-tuple. For example, a 2-tuple for a packet may refer to thecombination of <source network address, destination network address> or<source network address, source port> for the packet.

Servers 12 may each represent a compute server, switch, or storageserver. For example, each of servers 12 may represent a computingdevice,such as an x86 processor-based server, configured to operateaccording to techniques described herein. Servers 12 may provide NetworkFunction Virtualization Infrastructure (NFVI) for an NFV architecture.

Any server of servers 12 may be configured with virtual executionelements by virtualizing resources of the server to provide an isolationamong one or more processes (applications) executing on the server.“Hypervisor-based” or “hardware-level” or “platform” virtualizationrefers to the creation of virtual machines that each includes a guestoperating system for executing one or more processes. In general, avirtual machine provides a virtualized/guest operating system forexecuting applications in an isolated virtual environment. Because avirtual machine is virtualized from physical hardware of the hostserver, executing applications are isolated from both the hardware ofthe host and other virtual machines. Each virtual machine may beconfigured with one or more virtual network interfaces for communicatingon corresponding virtual networks.

Virtual networks are logical constructs implemented on top of thephysical networks. Virtual networks may be used to replace VLAN-basedisolation and provide multi-tenancy in a virtualized data center, e.g.,data center 10. Each tenant or an application can have one or morevirtual networks. Each virtual network may be isolated from all theother virtual networks unless explicitly allowed by security policy.

Virtual networks can be connected to, and extended across physicalMulti-Protocol Label Switching (MPLS) Layer 3 Virtual Private Networks(L3VPNs) and Ethernet Virtual Private Networks (EVPNs) networks using adatacenter 10 edge router (not shown in FIG. 1). Virtual networks mayalso used to implement Network Function Virtualization (NFV) and servicechaining.

Virtual networks can be implemented using a variety of mechanisms. Forexample, each virtual network could be implemented as a Virtual LocalArea Network (VLAN), Virtual Private Networks (VPN), etc. A virtualnetwork can also be implemented using two networks—the physical underlaynetwork made up of IP fabric 20 and switching fabric 14 and a virtualoverlay network. The role of the physical underlay network is to providean “IP fabric,” which provides unicast IP connectivity from any physicaldevice (server, storage device, router, or switch) to any other physicaldevice. The underlay network may provide uniform low-latency,non-blocking, high-bandwidth connectivity from any point in the networkto any other point in the network.

As described further below with respect to router 21A, virtual routersrunning in the kernels or hypervisors of the visualized servers 12create a virtual overlay network on top of the physical underlay networkusing a mesh of dynamic “tunnels” amongst themselves, These overlaytunnels can be MPLS over GRE/UDP tunnels, or VXLAN tunnels, or NVGREtunnels, for instance. The underlay physical routers and switches maynot contain any per-tenant state for virtual machines or other virtualexecution elements, such as any Media Access Control (MAC) addresses, IPaddress, or policies. The forwarding tables of the underlay physicalrouters and switches may, for example, only contain the IP prefixes orMAC addresses of the physical servers 12. (Gateway routers or switchesthat connect a virtual network to a physical network are an exceptionand may contain tenant MAC or IP addresses.)

Virtual routers 21 of servers 12 often contain per-tenant state. Forexample, they may contain a separate forwarding table (arouting-instance) per virtual network. That forwarding table containsthe IP prefixes (in the case of a layer 3 overlays) or the MAC addresses(in the case of layer 2 overlays) of the virtual machines or othervirtual execution elements (e.g., pods of containers). No single virtualrouter 21 needs to contain all TP prefixes or all MAC addresses for allvirtual machines in the entire data center. A given virtual router 21only needs to contain those routing instances that are locally presenton the server 12 (i.e. which have at least one virtual execution elementpresent on the server 12.)

The control plane protocol between the control plane nodes of thenetwork controller 24 or a physical gateway router (or switch) may beBGP (and may be Netconf for management). This is the same control planeprotocol may also be used for MPLS L3VPNs and MPLS EVPNs. The protocolbetween the network controller 24 and the virtual routers 21 may bebased on XMPP, for instance. The schema of the messages exchanged overXMPP may accord with Mackie et. al, “BGP-Signaled End-System IP/VPNs,”draft-ietf-13vpn-end-system-06, Dec. 15, 2016, which is incorporated byreference herein in its entirety.

“Container-based” or “operating system” virtualization refers to thevirtualization of an operating system to run multiple isolated systemson a single machine (virtual or physical). Such isolated systemsrepresent containers, such as those provided by the open-source DOCKERContainer application or by CoreOS Rkt (“Rocket”). Like a virtualmachine, each container is virtualized and may remain isolated from thehost machine and other containers. However, unlike a virtual machine,each container may omit an individual operating system and provide onlyan application suite and application-specific libraries. In general, acontainer is executed by the host machine as an isolated user-spaceinstance and may share an operating system and common libraries withother containers executing on the host machine. Thus, containers mayrequire less processing power, storage, and network resources thanvirtual machines. A group of one or more containers may be configured toshare one or more virtual network interfaces for communicating oncorresponding virtual networks.

In some examples, containers are managed by their host kernel to allowlimitation and prioritization of resources (CPU, memory, block I/O,network, etc.) without the need for starting any virtual machines, insome cases using namespace isolation functionality that allows completeisolation of an application's (e.g., a given container) view of theoperating environment, including process trees, networking, useridentifiers and mounted file systems. In some examples, containers maybe deployed according to Linux Containers (LXC), anoperating-system-level virtualization method for running multipleisolated Linux systems (containers) on a control host using a singleLinux kernel. LXC is an operating-system-level virtualization method forrunning multiple isolated Linux systems (containers) on a single controlhost (LXC host). An LXC does not use a virtual machine (although an LXCmay be hosted by a virtual machine). Instead, an LXC uses a virtualenvironment with its own CPU, memory, block I/O, network, and/or otherresource space. The LXC resource control mechanism is provided bynamespaces and coups in the Linux kernel on the LXC host. Additionalinformation regarding containers is found in “Docker Overview,” Docker,Inc., available at docs.dockercom/engine/understanding-docker, lastaccessed July 9, 2016. Additional examples of containerization methodsinclude OpenVZ, FreeBSD jail, AIX Workload partitions, and Solariscontainers. Accordingly, as used herein, the term “containers” mayencompass not only LXC-style containers but also any one or more ofvirtualization engines, virtual private servers, silos, or jails.

Servers 12 host virtual network endpoints for one or more virtualnetworks that operate over the physical network represented here by IPfabric 20 and switch fabric 14. Although described primarily withrespect to a data center-based switching network, other physicalnetworks, such as service provider network 7, may underlay the one ormore virtual networks.

Each of servers 12 may host one or more virtual execution elements eachhaving at least one virtual network endpoint for one or more virtualnetworks configured in the physical network. A virtual network endpointfor a virtual network may represent one or more virtual executionelements that share a virtual network interface for the virtual network.For example, a virtual network endpoint may be a virtual machine, a setof one or more containers (e.g., a pod), or another other virtualexecution element(s), such as a layer 3 endpoint for a virtual network.The term “virtual execution element” encompasses virtual machines,containers, and other virtualized computing resources that provide an atleast partially independent execution environment for applications. Theterm “virtual execution element” may also encompass a. pod of one ormore containers. As shown in FIG. 1, server 12A hosts one virtualnetwork endpoint in the form of pod 22A having one or more containers.However, a server 12 may execute as many virtual execution elements asis practical given hardware resource limitations of the server 12. Eachof the virtual network endpoints may use one or more virtual networkinterfaces to perform packet I/O or otherwise process a packet. Forexample, a virtual network endpoint may use one virtual hardwarecomponent (e.g., an SR-IOV virtual function) enabled by NIC 13A toperform packet I/O and receive/send packets on one or more communicationlinks with TOR switch 16A. Other examples of virtual network interfacesare described below.

Servers 12 each includes at least one network interface card (NIC) 13,which each includes at least one interface to exchange packets with TORswitches 16 over a communication link. For example, server 12A includesNIC 13A. Any of NICs 13 may provide one or more virtual hardwarecomponents 2.1 for virtualized input/output (I/O). A virtual hardwarecomponent for I/O maybe a virtualization of a physical NIC 13 (the“physical function”). For example, in Single Root I/O Virtualization(SR-IOV), which is described in the Peripheral Component InterfaceSpecial Interest Group SR-IOV specification, the PCIe Physical Functionof the network interface card (or “network adapter”) is virtualized topresent one or more virtual network interfaces as “virtual functions”for use by respective endpoints executing on the server 12. In this way,the virtual network endpoints may share the same PCIe physical hardwareresources and the virtual functions are examples of virtual hardwarecomponents 21. As another example, one or more servers 12 may implementVirtio, a para-virtualization framework available, e.g., for the LinuxOperating System, that provides emulated NIC functionality as a type ofvirtual hardware component to provide virtual network interfaces tovirtual network endpoints. As another example, one or more servers 12may implement Open vSwitch to perform distributed virtual multilayerswitching between one or more virtual NICs (vNICs) for hosted virtualmachines, where such vNICs may also represent a type of virtual hardwarecomponent that provide virtual network interfaces to virtual networkendpoints. In some instances, the virtual hardware components arevirtual I/O (e.g., NIC) components. In some instances, the virtualhardware components are SR-IOV virtual functions. In some examples, anyserver of servers 12 may implement a Linux bridge that emulates ahardware bridge and forwards packets among virtual network interfaces ofthe server or between a virtual network interface of the server and aphysical network interface of the server. For Docker implementations ofcontainers hosted by a server, a Linux bridge or other operating systembridge, executing on the server, that switches packets among containersmay be referred to as a “Docker bridge.” The term “virtual router” asused herein may encompass an Open vSwitch (OVS), an OVS bridge, a Linuxbridge, Docker bridge, or other device and/or software that is locatedon a host device and performs switching, bridging, or routing packetsamong virtual network endpoints of one or more virtual networks, wherethe virtual network endpoints are hosted by one or more of servers 12.

Any of NICs 13 may include an internal device switch to switch databetween virtual hardware components 21 associated with the NIC. Forexample, for an SR-IOV-capable NIC, the internal device switch may be aVirtual Ethernet Bridge (VETS) to switch between the SR-IOV virtualfunctions and, correspondingly, between endpoints configured to use theSR-IOV virtual functions, where each endpoint may include a guestoperating system. Internal device switches may be alternatively referredto as MC switches or, for SR-IOV implementations, SR-IOV NIC switches.Virtual hardware components associated with NIC 13A may be associatedwith a layer 2 destination address, which may be assigned by the MC 13Aor a software process responsible for configuring NIC 13A. The physicalhardware component (or “physical function” for SR-IOV implementations)is also associated with a layer 2 destination address.

To switch data between virtual hardware components associated with NIC13A, internal device switch may perform layer 2 forwarding to switch orbridge layer 2 packets between virtual hardware components and thephysical hardware component for NIC 13A. Each virtual hardware componentmay be located on a virtual local area network (ULAN) for the virtualnetwork for the virtual network endpoint that uses the virtual hardwarecomponent for I/O, Further example details of SR-I0V implementationswithin a MC are described in “PCI-SIG SR-IOV Primer: An Introduction toSR-IOV Technology,” Rev. 2.5, Intel Corp., January, 2011, which isincorporated herein by reference in its entirety.

One or more of servers 12 may each include a virtual router 21 thatexecutes one or more routing instances for corresponding virtualnetworks within data center 10 to provide virtual network interfaces androute packets among the virtual network endpoints. Each of the routinginstances may be associated with a network forwarding table. Each of therouting instances may represent a virtual routing and forwardinginstance (VRF) for an Internet Protocol-Virtual Private Network(IP-VPN). Packets received by the virtual router 21A (illustrated as“vROUTER 21A”) of server 12A, for instance, from the underlying physicalnetwork fabric of data center 10 IP fabric 20 and switch fabric 14) mayinclude an outer header to allow the physical network fabric to tunnelthe payload or “inner packet” to a physical network address for anetwork interface card 13A of server 12A that executes the virtualrouter. The outer header may include not only the physical networkaddress of the network interface card 13A of the server but also avirtual network identifier such as a VxLAN tag or Multiprotocol LabelSwitching (MPLS) label that identifies one of the virtual networks aswell as the corresponding routing instance executed by the virtualrouter 21A. An inner packet includes an inner header having adestination network address that conforms to the virtual networkaddressing space for the virtual network identified by the virtualnetwork identifier.

Virtual routers 21 terminate virtual network overlay tunnels anddetermine virtual networks for received packets based on tunnelencapsulation headers for the packets, and forwards packets to theappropriate destination virtual network endpoints for the packets. Forserver 12A, for example, for each of the packets outbound from virtualnetwork endpoints hosted by server 12A (e.g., pod 22A), the virtualrouter 21A attaches a tunnel encapsulation header indicating the virtualnetwork for the packet to generate an encapsulated or “tunnel” packet,and virtual router 21A outputs the encapsulated packet via overlaytunnels for the virtual networks to a physical destination computingdevice, such as another one of servers 12. As used herein, a virtualrouter 21 may execute the operations of a tunnel endpoint to encapsulateinner packets sourced by virtual network endpoints to generate tunnelpackets and decapsulate tunnel packets to obtain inner packets forrouting to other virtual network endpoints.

Computing infrastructure 8 implements an automation platform forautomating deployment, scaling, and operations of virtual executionelements across servers 12 to provide virtualized infrastructure forexecuting application workloads and services. In some examples, theplatform may be a container orchestration platform that provides acontainer-centric infrastructure for automating deployment, scaling, andoperations of containers to provide a container-centric infrastructure.“Orchestration,” in the context of a virtualized computinginfrastructure generally refers to provisioning, scheduling, andmanaging virtual execution elements and/or applications and servicesexecuting on such virtual execution elements to the host serversavailable to the orchestration platform. Container orchestration,specifically, permits container coordination and refers to thedeployment, management, scaling, and configuration, e.g., of containersto host servers by a container orchestration platform. Example instancesof orchestration platforms include Kubernetes, Docker swarm,Mesos/Marathon, OpenShift, OpenStack, VMware, and Amazon ECS.

Elements of the automation platform of computing infrastructure 8include at least servers 12, orchestrator 23, and network controller 24.Virtual execution elements may be deployed to a virtualizationenvironment using a cluster-based framework in which a cluster masternode of a cluster manages the deployment and operation of containers toone or more cluster minion nodes of the cluster. The terms “master node”and “minion node” used herein encompass different orchestration platformterms for analogous devices that distinguish between primarilymanagement elements of a cluster and primarily virtual execution elementhosting devices of a cluster. For example, the Kubernetes platform usesthe terms “cluster master” and “minion nodes,” while the Docker Swarmplatform refers to cluster managers and cluster nodes.

Orchestrator 23 and network controller 24 together implement acontroller 5 for the computing infrastructure 8. Orchestrator 23 andnetwork controller 24 may execute on separate computing devices, executeon the same computing device. Each of orchestrator 23 and networkcontroller 24 may be a distributed application that executes on one ormore computing devices. Orchestrator 23 and network controller 24 mayimplement respective master nodes for one or more clusters each havingone or more minion nodes implemented by respective servers 12. Ingeneral, network controller 24 controls the network configuration of thedata center 10 fabric to, e.g., establish one or more virtual networksfor packetized communications among virtual network endpoints. Networkcontroller 24 provides a logically and in some cases physicallycentralized controller for facilitating operation of one or more virtualnetworks within data center 10. In some examples, network controller 24may operate in response to configuration input received fromorchestrator 23 and/or an administrator/operator. Additional informationregarding network controller 24 operating in conjunction with otherdevices of data center 10 or other software-defined network is found inInternational Application Number PCT/US2013/044378, filed Jun. 5, 2013,and entitled “PHYSICAL PATH DETERMINATION FOR VIRTUAL NETWORK PACKETFLOWS;” and in U.S. patent application Ser. No. 14/226,509, filed Mar.26, 2014, and entitled “Tunneled Packet Aggregation for VirtualNetworks,” each which is incorporated by reference as if fully set forthherein. U.S. patent application Ser. No. 14/226,509 also includesfurther description of a virtual router, such as virtual router 21A.

In general, orchestrator 23 controls the deployment, scaling, andoperations of virtual execution elements across clusters of servers 12and providing computing infrastructure, which may includecontainer-centric computing infrastructure. Orchestrator 23 and, in somecases, network controller 24 may implement respective cluster mastersfor one or more Kubernetes clusters. As an example, Kubernetes is acontainer management platform that provides portability across publicand private clouds, each of which may provide virtualizationinfrastructure to the container management platform.

In one example, pod 22A is a Kubernetes pod and an example of a virtualnetwork endpoint. A pod is a group of one or more logically-relatedcontainers (not shown in FIG. 1), the shared storage for the containers,and options on how to run the containers. Where instantiated forexecution, a pod may alternatively be referred to as a “pod replica.”Each container of pod 22A is an example of a virtual execution element.Containers of a pod are always co-located on a single server,co-scheduled, and run in a shared context. The shared context of a podmay be a set of Linux namespaces, egroups, and other facets ofisolation. Within the context of a pod, individual applications mighthave further sub-isolations applied. Typically, containers within a podhave a common IP address and port space and are able to detect oneanother via the localhost. Because they have a shared context,containers within a pod are also communicate with one another usinginter-process communications (IPC). Examples of IPC include SystemVsemaphores or POSIX shared memory. Generally, containers that aremembers of different pods have different IP addresses and are unable tocommunicate by IPC in the absence of a configuration for enabling thisfeature. Containers that are members of different pods instead usuallycommunicate with each other via pod IP addresses.

Server 12A includes a container platform 19A for running containerizedapplications, such as those of pod 22A. Container platform 19A receivesrequests from orchestrator 23 to obtain and host, in server 12A,containers. Container platform 19A obtains and executes the containers.

Container platform 19A includes a network module 17A that configuresvirtual network interfaces for virtual network endpoints. The containerplatform 19A uses network module 17A to manage networking for pods,including pod 22A. For example, the network module 17A creates virtualnetwork interfaces to connect pods to virtual router 21A and enablecontainers of such pods to communicate, via the virtual networkinterfaces, to other virtual network endpoints over the virtualnetworks. Network module 17A may, for example, insert a virtual networkinterface for a virtual network into the network namespace forcontainers of in pod 22A and configure (or request to configure) thevirtual network interface for the virtual network in virtual router 21Asuch that the virtual router 21A is configured to send packets receivedfrom the virtual network via the virtual network interface to containersof pod 22A and to send packets received via the virtual networkinterface from containers of pod 22A on the virtual network. Networkmodule 17A may assign a network address (e.g., a virtual IP address forthe virtual network) and may setup routes for the virtual networkinterface. In Kubernetes, by default all pods can communicate with allother pods without using network address translation (NAT). In somecases, the orchestrator 23 and network controller 24 create a servicevirtual network and a pod virtual network that are shared by allnamespaces, from which service and pod network addresses are allocated,respectively. In some cases, all pods in all namespaces that are spawnedin the Kubernetes cluster may be able to communicate with one another,and the network addresses for all of the pods may be allocated from apod subnet that is specified by the orchestrator 23. When a user createsan isolated namespace for a pod, orchestrator 23 and network controller24 may create a new pod virtual network and new shared service virtualnetwork for the new isolated namespace. Pods in the isolated namespacethat are spawned in the Kubernetes cluster draw network addresses fromthe new pod virtual network, and corresponding services for such podsdraw network addresses from the new service virtual network

Network module 17A may represent a library, a plugin, a module, aruntime, or other executable code for server 12A. Network module 17A mayconform, at least in part, to the Container Networking Interface (CNI)specification or the rkt Networking Proposal. Network module 17A mayrepresent a Contrail or OpenContrail network plugin. Network module 17Amay alternatively be referred to as a network plugin or CNI plugin orCNI instance. For purposes of the CNI specification, a container can beconsidered synonymous with a Linux network namespace. What unit thiscorresponds to depends on a particular container runtime implementation:for example, in implementations of the application containerspecification such as rkt, each pod runs in a unique network namespaceIn Docker, however, network namespaces generally exist for each separateDocker container. For purposes of the CNI specification, a networkrefers to a group of entities that are uniquely addressable and that cancommunicate amongst each other. This could be either an individualcontainer, a machine/server (real or virtual), or some other networkdevice (e.g. a router). Containers can be conceptually added to orremoved from one or more networks.

The CNI specification specifies a number of considerations for aconforming plugin (“CNI plugin”). These include the following:

-   -   The container runtime must create a new network namespace for a        container before invoking any CNI plugin.    -   The container runtime must then determine which networks this        container should belong to, and for each network, which plugins        must be executed.    -   The container runtime must add the container to each network by        executing the corresponding plugins for each network        sequentially.

In accordance with techniques of this disclosure, the single networkmodule 17A configures, for pod 22A, multiple virtual network interfaces26A-26N (“virtual network interfaces”) for corresponding virtualnetworks configured in switch fabric 14, where any of the containers ofthe pod 22A may utilize, i.e., share, any of the multiple virtualnetwork interfaces 26. In this way, and as described further below,network module 17A addresses certain limitations of CNI plugins thatconform strictly to the CNI specification.

Each of virtual network interfaces 26 may represent a virtual ethernet(“veth”) pair, where each end of the pair is a separate device (e.g., aLinux/Unix device), with one end of the pair assigned to pod 22A and oneend of the pair assigned to virtual router 22A. The veth pair or an endof a veth pair are sometimes referred to as “ports”. Each of virtualnetwork interfaces 26 may alternatively represent a macvlan network withmedia access control (MAC) addresses assigned to the pod 22A and to thevrouter 21A for communications between containers of pod 22A and vrouter21A. Each of virtual network interfaces 26 may alternatively represent adifferent type of interface between virtual router 21A or other networkvirtualization entity and virtual network endpoints. Virtual networkinterfaces 26 may alternatively be referred to as virtual machineinterfaces (VMIs), pod interfaces, container network interfaces, tapinterfaces, veth interfaces, or simply network interfaces (in specificcontexts), for instance.

In the example server 12A of FIG. 1, pod 22A is a virtual networkendpoint in multiple different virtual networks. Orchestrator 23 maystore or otherwise manage configuration data for application deploymentsthat specifies the multiple virtual networks and specifies that pod 22A(or the one or more containers therein) is a virtual network endpoint ofeach of the multiple virtual networks. Orchestrator 23 may receive theconfiguration data from a user, operator/administrator, or other machinesystem, for instance.

As part of the process of creating pod 22A, orchestrator 23 sendsrequest 29 to request that network controller 24 create respectivevirtual network interfaces for the multiple virtual networks (indicatedin the configuration data). Network controller 24 processes request 29to generate interface configuration data 25 for the multiple virtualnetwork interfaces 26 for pod 22A. Interface configuration data 25 mayinclude a container or pod unique identifier and a list or other datastructure specifying, for each of virtual network interface 26, networkconfiguration data for configuring the virtual network interface.Network configuration data for a virtual network interface may include anetwork name, assigned virtual network address, MAC address, and/ordomain name server values. An example of network configuration data inJavascript Object Notation (JSON) format is below. The multiple virtualnetwork interfaces 26 correspond, respectively, to the multiple virtualnetworks. Network controller 24 sends interface configuration data 25 toserver 12A and, more specifically in some cases, to virtual router 21A.To configure one or more virtual network interfaces for pod 22A,container platform 19A may, in some implementations, invoke a singleinstance of network module 17A. The network module 17A obtains andprocesses the interface configuration data 25. For each virtual networkinterface specified in the interface configuration data 25, the networkmodule 17A creates one of virtual network interfaces 26. For example,network module 17A may attach one end of a veth pair implementingvirtual network interface 26A to virtual router 21A and may attach theother end of the same veth pair to pod 22A. Similarly, network module17A may attach one end of a veth pair implementing virtual networkinterface 26N to virtual router 21A and may attach the other end of thesame veth pair to pod 22A. In this way, a single instance of networkmodule 17A configures multiple virtual network interfaces 26 for one ormore virtual execution element that share at least one virtual networkinterface, in this case pod 22A.

The following is example network configuration data for pod 22A formultiple virtual network interfaces 26A-26N, where in this case, N=3.

[{  // virtual network interface 26A  ″id″:″fe4bab62-a716-11e8-abd5-0cc47a698428″,  ″instance-id″:″fe3edca5-a716-11e8-822c-0cc47a698428″,  ″ip-address″: ″10.47.255.250″, ″plen″: 12,  ″vn-id″: ″56dda39c-5e99-4a28-855e-6ce378982888″, ″vm-project-id″: ″00000000-0000-0000-0000-000000000000″, ″mac-address″: ″02:fe:4b:ab:62:a7″,  ″system-name″: ″tapeth0fe3edca″, ″rx-van-id″: 65535,  ″tx-vlan-id″: 65535,  ″vhostuser-mode″: 0, “v6-ip-address”: “::“,  “v6-plen”: ,  “v6-dns-server”: “::”, “v6-gateway”: “::”,  ″dns-server″: ″10.47.255.253″,  ″gateway″:″10.47.255.254″,  ″author″: ″/usr/bin/contrail-vrouter-agent″,  ″time″:″426404:56:19.863169″ },{  // virtual network interface 26B  ″id″:″fe611a38-a716-11e8-abd5-0cc47a698428″,  ″instance-id″:″fe3edca5-a716-11e8-822c-0cc47a698428″,  ″ip-address″: ″30.1.1.252″, ″plen″: 24,  ″vn-id″: ″b0951136-a702-43d2-9e90-3e5a9343659d″, ″vm-project-id″: ″00000000-0000-0000-0000-000000000000″, ″mac-address″: ″02:fe:61:1a:38:a7″,  ″system-name″: ″tapeth1fe3edca″, ″rx-vlan-id″: 65535,  ″tx-vlan-id″: 65535,  ″vhostuser-mode″: 0, “v6-ip-address”: “::“,  “v6-plen”: ,  “v6-dns-server”: “::”, “v6-gateway”: “::”,  ″dns-server″: ″3011.253″,  ″gateway″:″30.1.1.254″,  ″author″: ″/usr/bin/contrail-vroute-agent″,  ″time″:″426404:56:19.863380″ },{  // virtual network interface 26N  ″id”:″fe7a52aa-a716-11e8-abd5-0cc47a698428”,  ″instance-id”:″fe3edca5-a716-11e8-822c-0cc47a698428”,  ″ip-address”: ″40.1.1.252”, ″plen”: 24,  ″ip6-address”: ″::”,  ″vn-id”:″200cb1e6-7138-4a55-a8df-936bb7515052”,  ″vm-project-id”:″00000000-0000-0000-0000-000000000000”,  ″mac-address”:″02:fe:7a:52:aa:a7”,  ″system-name”: ″tapeth2fe3edca”,  ″rx-vlan-id”:65535,  ″tx-vlan-id”: 65535,  ″vhostuser-mode”: 0,  “v6-ip-address”:“::“,  “v6-plen”: ,  “v6-dhs-server”: “::”,  “v6-gateway”: “::”, ″dns-server″: ″40.1.1.253″,  ″gateway″: ″40.1.1.254″,  ″author″:″/usr/bin/contrail-vrouter-agent″,  ″time″: ″426404:56:19.863556″ }]

A conventional CNI plugin is invoked by a container platform/runtime,receives an Add command from the container platform to add a containerto a single virtual network, and such a plugin may subsequently beinvoked to receive a Del(ete) command from the container/runtime andremove the container from the virtual network. The Add command supportsonly adding a single virtual network and must be invoked multiple timesin order to add a pod to multiple virtual networks. A single networkmodule 17A invoked by container platform 19A extends the functionalityof a conventional CNI plugin by obtaining interface configuration data25 and adding multiple different virtual network interfaces 26. The term“invoke” may refer to the instantiation, as executable code, of asoftware component or module in memory (e.g., user space 245) forexecution by microprocessor 210.

FIG. 2 is a block diagram of an example computing device (e.g., host)that includes a network module for configuring multiple virtual networkinterfaces for a set of one or more virtual execution elements thatshare at least one virtual network interface, according to techniquesdescribed in this disclosure. Computing device 200 of FIG. 2 mayrepresent a real or virtual server and may represent an example instanceof any of servers 12 of FIG. 1. Computing device 200 includes in thisexample, a bus 242 coupling hardware components of a computing device20( )hardware environment. Bus 242 couples network interface card (NIC)230, storage disk 246, and one or more microprocessors 210 (hereinafter,“microprocessor 210”). NIC 230 may be SR-WV-capable. A front-side busmay in sonic cases couple microprocessor 210 and memory device 244. Insome examples, bus 242 may couple memory device 244, microprocessor 210,and NIC 230. Bus 242 may represent a Peripheral Component Interface(PCI) express (PCIe) bus. In some examples, a direct memory access (DMA)controller may control DMA transfers among components coupled to bus242. In some examples, components coupled to bus 242 control DMAtransfers among components coupled to bus 242.

Microprocessor 210 may include one or more processors each including anindependent execution unit to perform instructions that conform to aninstruction set architecture, the instructions stored to storage media.Execution units may be implemented as separate integrated circuits (ICs)or may be combined within one or more multi-core processors (or“many-core” processors) that are each implemented using a single (i.e.,a chip multiprocessor).

Disk 246 represents computer readable storage media that includesvolatile and/or non-volatile, removable and/or non-removable mediaimplemented in any method or technology for storage of information suchas processor-readable instructions, data structures, program modules, orother data. Computer readable storage media includes, but is not limitedto, random access memory (RAM), read-only memory (ROM), EEPROM, Flashmemory, CD-ROM, digital versatile discs (MD) or other optical storage,magnetic cassettes, magnetic tape, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to storethe desired information and that can be accessed by microprocessor 210.

Main memory 244 includes one or more computer-readable storage media,which may include random-access memory (RAM) such as various forms ofdynamic RAM (DRAM), e.g., DDR2/DDR3 SDRAM, or static RAM (SRAM), flashmemory, or any other form of fixed or removable storage medium that canbe used to carry or store desired program code and program data in theform of instructions or data structures and that can be accessed by acomputer. Main memory 244 provides a physical address space composed ofaddressable memory locations.

Network interface card (NIC) 230 includes one or more interfaces 232configured to exchange packets using links of an underlying physicalnetwork. Interfaces 232 may include a port interface card having one ormore network ports. NIC 230 may also include an on-card memory to, e.g.,store packet data. Direct memory access transfers between the MC 230 andother devices coupled to bus 242 may read/write from/to the NIC memory.

Memory 244, NIC 230, storage disk 246, and microprocessor 210 mayprovide an operating environment for a software stack that includes anoperating system kernel 214 executing in kernel space. Kernel 214 mayrepresent, for example, a Linux, Berkeley. Software Distribution (BSD),another Unix-variant kernel, or a Windows server operating systemkernel, available from Microsoft Corp, In some instances, the operatingsystem may execute a hypervisor and one or more virtual machines managedby hypervisor. Example hypervisors include Kernel-based Virtual Machine(KVM) for the Linux kernel, Xen, ESXi available from VMware, WindowsI-Iyper-V available from Microsoft, and other open-source andproprietary hypervisors. The term hypervisor can encompass a virtualmachine manager (VMM). An operating system that includes kernel 214provides an execution environment for one or more processes in userspace 245.

Kernel 214 includes a physical driver 225 to use the network interfacecard 230. Network interface card 230 may also implement SR-IOV to enablesharing the physical network function (I/O) among one or more virtualexecution elements, such as containers 229A-229B or one or more virtualmachines (not shown in 2). Shared virtual devices such as virtualfunctions may provide dedicated resources such that each of the virtualexecution elements may access dedicated resources of NIC 230, whichtherefore appears to each of the virtual execution elements as adedicated NIC. Virtual functions may represent lightweight PCIefunctions that share physical resources with a physical function used byphysical driver 225 and with other virtual functions. For anSR-IOV-capable MC 230, NIC 230 may have thousands of available virtualfunctions according to the SR-IOV standard, but for I/O-intensiveapplications the number of configured virtual functions is typicallymuch smaller.

Computing device 200 may be coupled to a physical network switch fabricthat includes an overlay network that extends switch fabric fromphysical switches to software or “virtual” routers of physical serverscoupled to the switch fabric, including virtual router 220. Virtualrouters may be processes or threads, or a component thereof, executed bythe physical servers, e.g., servers 12 of FIG. 1, that dynamicallycreate and manage one or more virtual networks usable for communicationbetween virtual network endpoints. In one example, virtual routersimplement each virtual network using an overlay network, which providesthe capability to decouple an endpoint's virtual address from a physicaladdress (e.g., IP address) of the server on which the endpoint isexecuting. Each virtual network may use its own addressing and securityscheme and may be viewed as orthogonal from the physical network and itsaddressing scheme. Various techniques may be used to transport packetswithin and across virtual networks over the physical network. The term“virtual router” as used herein may encompass an Open vSwitch (OVS), anOVS bridge, a Linux bridge, Docker bridge, or other device and/orsoftware that is located on a host device and performs switching,bridging, or routing packets among virtual network endpoints of one ormore virtual networks, where the virtual network endpoints are hosted byone or more of servers 12. In the example computing device 200 of FIG.2, virtual router 220 executes within kernel 214, but virtual router 220may execute within a hypervisor, a host operating system, a hostapplication, or a virtual machine in various implementations.

Virtual router 220 may replace and subsume the virtual routing/bridgingfunctionality of the Linux bridge/OVS module that is commonly used forKubemetes deployments of pods 202. Virtual router 220 may performbridging (e.g., E-VPN) and routing (e.g., L3VPN, IP-VPNs) for virtualnetworks. Virtual router 220 may perform networking services such asapplying security policies, NAT, multicast, mirroring, and loadbalancing. Additional details for IIP-VPNs are described in “BGP/MPLS IPVirtual Private Networks (VPNs),” Request for Comments 4364, InternetEngineering Task Force Network Working Group, February 2006, hereinafter“RFC 4364,” which is incorporated by reference herein in its entirety.Virtual router 220 may represent a PE router and virtual executionendpoints may be examples of CE devices described in RFC 4364.

In general, each of pods 202A-202B may be assigned one or more virtualnetwork addresses for use within respective virtual networks, where eachof the virtual networks may be associated with a different virtualsubnet provided by virtual router 220. Pod 202B may be assigned its ownvirtual layer three (L3) IP address, for example, for sending andreceiving communications but may be unaware of an IP address of thecomputing device 200 on which the pod 202B. The virtual network addressmay thus differ from the logical address for the underlying, physicalcomputer system, e.g., computing device 200.

Computing device 200 includes a virtual router agent 216 that controlsthe overlay of virtual networks for computing device 200 and thatcoordinates the routing of data packets within computing device 200. Ingeneral, virtual router agent 216 communicates with network controller24 for the virtualization infrastructure, which generates commands tocontrol create virtual networks and configure network virtualizationendpoints, such as computing device 200 and, more specifically, virtualrouter 220, as a well as virtual network interfaces 212, 213. Byconfiguring virtual router 220 based on information received fromnetwork controller 24, virtual router agent 216 may support configuringnetwork isolation, policy-based security, a gateway, source networkaddress translation (SNRT), a load-balancer, and service chainingcapability for orchestration.

In one example, network packets, e.g., layer three (L3) IP packets orlayer two (L2) Ethernet packets generated or consumed by the containers22A-229B within the virtual network domain may be encapsulated inanother packet (e.g., another IP or Ethernet packet) that is transportedby the physical network. The packet transported in a virtual network maybe referred to herein as an “inner packet” while the physical networkpacket may be referred to herein as an “outer packet” or a “tunnelpacket.” Encapsulation and/or de-capsulation of virtual network packetswithin physical network packets may be performed by virtual router 220.This functionality is referred to herein as tunneling and may be used tocreate one or more overlay networks. Besides IPinIP, other exampletunneling protocols that may be used include IP over Generic RouteEncapsulation (GRE), VxLAN, Multiprotocol Label Switching (MPLS) overGRE, MPLS over User Datagram Protocol (UDP), etc. Virtual router 220performs tunnel encapsulation/decapsulation for packets sourcedby/destined to any containers of pods 202, and virtual router 220exchanges packets with pods 202 via bus 242 and/or a bridge of NIC 230.

As noted above, a network controller 24 may provide a logicallycentralized controller for facilitating operation of one or more virtualnetworks. The network controller 24 may, for example, maintain a routinginformation base, e.g., one or more routing tables that store routinginformation for the physical network as well as one or more overlaynetworks. Virtual router 220 implements one or more virtual routing andforwarding instances (VRFs) 222A-222B for respective virtual networksfor which virtual router 220 operates as respective tunnel endpoints. Ingeneral, each VRF 222 stores forwarding information for thecorresponding virtual network and identifies where data packets are tobe forwarded and whether the packets are to be encapsulated in atunneling protocol, such as with a tunnel header that may include one ormore headers for different layers of the virtual network protocol stack.Each of VRF's 222 may include a network forwarding table storing routingand forwarding information for the virtual network.

NIC 230 may receive tunnel packets. Virtual router 220 processes thetunnel packet to determine, from the tunnel encapsulation header, thevirtual network of the source and destination endpoints for the innerpacket. Virtual router 220 may strip the layer 2 header and the tunnelencapsulation header to internally forward only the inner packet. Thetunnel encapsulation header may include a virtual network identifier,such as a VxLAN tag or MPLS label, that indicates a virtual network,e.g., a virtual network corresponding to VRF 222A. VRF 222A may includeforwarding information for the inner packet. For instance, VRF 222A maymap a destination layer 3 address for the inner packet to virtualnetwork interface 212A. VRF 222A forwards the inner packet via virtualnetwork interface 212A to POD 202A in response.

Containers 229A-229B may also source inner packets as source virtualnetwork endpoints. Container 229A, for instance, may generate a layer 3inner packet destined for a destination virtual network endpoint that isexecuted by another computing device (i.e., not computing device 200) orfor another one of containers 229A-229B. Container 229A sends the layer3 inner packet to virtual router 220 via virtual network interface 212Aattached to VRF 222A.

Virtual router 220 receives the inner packet and layer 2 header anddetermines a virtual network for the inner packet. Virtual router 220may determine the virtual network using any of the above-describedvirtual network interface implementation techniques (e.g., macvlan,veth, etc.). Virtual router 220 uses the VRF 222A corresponding to thevirtual network for the inner packet to generate an outer header for theinner packet, the outer header including an outer IP header for theoverlay tunnel and a tunnel encapsulation header identifying the virtualnetwork. Virtual router 220 encapsulates the inner packet with the outerheader. ‘Virtual router 220 may encapsulate the tunnel packet with a newlayer 2 header having a destination layer 2 address associated with adevice external to the computing device 200, e.g., a TOR switch 16 orone of servers 12. If external to computing device 200, virtual router220 outputs the tunnel packet with the new layer 2 header to NIC 230using physical function 221. NIC 230 outputs the packet on an outboundinterface. If the destination is another virtual network endpointexecuting on computing device 200, virtual router 220 routes the packetto the appropriate one of virtual network interfaces 212, 213.

In some examples, a controller for computing device 200 (e.g., networkcontroller 24 of FIG. 1) configures a default route in each of pods 202to cause the virtual machines 224 to use virtual router 220 as aninitial next hop for outbound packets In some examples, NIC 230 isconfigured with one or more forwarding rules to cause all packetsreceived from virtual machines 224 to be switched to virtual router 220.

Pods 202N-202B may represent example instances of pod 22A of FIG. 1, infurther detail. Pod 202A includes one or more containers 229A, and pod202B includes one or more containers 229B.

Container platform 204 may represent an example instance of containerplatform 19A of FIG. 1, in further detail. Container platform 204include container runtime 208, orchestration agent 209, service proxy211, and network modules 206A-206B. Each of network modules 206A-206Bmay represent an example instance of network module 17A of FIG. 1, therebeing invoked one network module 206 per pod 202.

Container engine 208 includes code executable by microprocessor 210.Container runtime 208 may be one or more computer processes. Containerengine 208 runs containerized applications in the form of containers229A-229B. Container engine 208 may represent a Dockert, rkt, or othercontainer engine for managing containers. In general, container engine208 receives requests and manages objects such as images, containers,networks, and volumes. An image is a template with instructions forcreating a container. A container is an executable instance of an image.Based on directives from controller agent 209, container engine 208 mayobtain images and instantiate them as executable containers 229A-229B inpods 202A-202B.

Service proxy 211 includes code executable by microprocessor 210.Service proxy 211 may be one or more computer processes. Service proxy211 monitors for the addition and removal of service and endpointsobjects, and it maintains the network configuration of the computingdevice 200 to ensure communication among pods and containers, e.g.,using services. Service proxy 211 may also manage iptables to capturetraffic to a service's virtual IP address and port and redirect thetraffic to the proxy port that proxies a backed pod. Service proxy 211may represent a kube-proxy for a minion node of a Kubemetes cluster. Insome examples, container platform 204 does not include a service proxy211 or the service proxy 211 is disabled in favor of configuration ofvirtual router 220 and pods 202 by network modules 206.

Orchestration agent 209 includes code executable by microprocessor 210.Orchestration agent 209 may be one or more computer processes,Orchestration agent 209 may represent a kubelet for a minion node of aKubernetes cluster. Orchestration agent 209 is an agent of anorchestrator, e.g., orchestrator 23 of FIG. 1, that receives containerspecification data for containers and ensures the containers execute bycomputing device 200. Container specification data may be in the form ofa manifest file sent to orchestration agent 209 from orchestrator 23 orindirectly received via a command line interface, HTTP endpoint, or HTTPserver. Container specification data may be a pod specification (e.g., aPod Spec—a YAML (Yet Another Markup Language) or JSON object thatdescribes a pod) for one of pods 202 of containers 229. Based on thecontainer specification data, orchestration agent 209 directs containerengine 208 to obtain and instantiate the container images for containers229, for execution of containers 229 by computing device 200.

In accordance with techniques described herein, orchestration agent 209instantiates a single one of network modules 206 to configure one ormore virtual network interfaces for each of pods 202. Each of networkmodules 206 may represent an example instance of network module 17A ofFIG. 1. For example, orchestration agent 209 receives a containerspecification data for pod 202A and directs container engine 208 tocreate the pod 202A with containers 229A based on the containerspecification data for pod 202A. Orchestration agent 209 also invokesthe single network module 206A to configure, for pod 202A, multiplevirtual network interfaces 212A-212B for virtual networks correspondingto VRFs 222A-222B, respectively. In a similar manner, orchestrationagent 209 directs container engine 208 to create the pod 202B withcontainers 229B based on the container specification data for pod 202B.Orchestration agent 209 also invokes the single network module 20613 toconfigure, for pod 202B, a virtual network interface 213 for a virtualnetwork corresponding to VRF 222B. In this example, both pod 202A andpod 202B are virtual network endpoints for the virtual networkcorresponding to VRF 22B. Any of virtual network interfaces 212, 213 mayrepresent an example instance of one of virtual network interfaces 26described in FIG. 1.

Network module 206A may obtain interface configuration data forconfiguring virtual network interfaces for pods 202. Virtual routeragent 216 operates as a virtual network control plane module forenabling network controller 24 to configure virtual router 220. Unlikethe orchestration control plane (including the container platforms 204for minion nodes and the master node(s), e.g., orchestrator 23), whichmanages the provisioning, scheduling, and managing virtual executionelements, a virtual network control plane (including network controller24 and virtual router agent 216 for minion nodes) manages theconfiguration of virtual networks implemented in the data plane in partby virtual routers 220 of the minion nodes. Virtual router agent 216communicates, to network modules 206, interface configuration data forvirtual network interfaces to enable an orchestration control planeelement (i.e., network module 206) to configure the virtual networkinterfaces according to the configuration state determined by thenetwork controller 24, thus bridging the gap between the orchestrationcontrol plane and virtual network control plane. In addition, this mayenable a single network module 206A to obtain interface configurationdata for multiple virtual network interfaces for a pod and configure themultiple virtual network interfaces, which may reduce communication andresource overhead inherent with invoking a separate network module 206for configuring each virtual network interface.

FIG. 3 is a block diagram of an example computing device operating as aninstance of controller for a virtualized computing infrastructure.Computing device 300 an example instance of controller 5 for avirtualized computing infrastructure. Computing device 300 of FIG. 3 mayrepresent one or more real or virtual servers configured to performoperations for at least one of a network controller 24 and anorchestrator 23. As such, computing device 300 may in some instancesimplement one or more master nodes for respective clusters.

Scheduler 322, API server 320, network controller manager 326, networkcontroller 324, network controller manager 325, and configuration store328, although illustrated and described as being executed by a singlecomputing device 300, may be distributed among multiple computingdevices 300 that make up a computing system or hardware/server cluster.Each of the multiple computing devices 300, in other words, may providea hardware operating environment for one or more instances of any one ormore of scheduler 322, API server 320, network controller manager 326,network controller 324, network controller manager 325, or configurationstore 328. Network controller 324 may represent an example instance ofnetwork controller 24 of FIG. 1. Scheduler 322, API server 320,controller manager 326, and network controller manager 325 may implementan example instance of orchestrator 23, Network controller manager 325may represent an example implementation of a Kubernetes cloud controllermanager. Network controller 324 may represent an example instance ofnetwork controller 24.

Computing device 300 includes in this example, a bus 342 couplinghardware components of a computing device 300 hardware environment. Bus342 couples network interface card (NIC) 330, storage disk 346, and oneor more microprocessors 310 (hereinafter, “microprocessor 310”). Afront-side bus may in some cases couple microprocessor 310 and memorydevice 344, In some examples, bus 342 may couple memory device 344,microprocessor 310, and NIC 330. Bus 342 may represent a PeripheralComponent Interface (PCI) express (PCIe) bus. In some examples, a directmemory access (DMA) controller may control DMA transfers amongcomponents coupled to bus 242. In some examples, components coupled tobus 342 control DMA transfers among components coupled to bus 342.

Microprocessor 310 may include one or more processors each including anindependent execution unit to perform instructions that conform to aninstruction set architecture, the instructions stored to storage media.Execution units may be implemented as separate integrated circuits (ICs)or may be combined within one or more multi-core processors (or“many-core” processors) that are each implemented using a single IC(i.e., a chip multiprocessor)

Disk 346 represents computer readable storage media that includesvolatile and/or non-volatile, removable and/or non-removable mediaimplemented in any method or technology for storage of information suchas processor-readable instructions, data structures, program modules, orother data. Computer readable storage media includes, but is not limitedto, random access memory (RAM), read-only memory (ROM), EEPROM, Flashmemory, CD-ROM, digital versatile discs (DVD) or other optical storage,magnetic cassettes, magnetic tape, magnetic disk storage or othermagnetic storage devices, or any other medium that can be used to storethe desired information and that can be accessed by microprocessor 310.

Main memory 344 includes one or more computer-readable storage media,which may include random-access memory (RAM) such as various forms ofdynamic RAM (DRAM), e.g., DDR2/DDR3 SDRAM, or static RAM (SRAM), flashmemory, or any other form of fixed or removable storage medium that canbe used to carry or store desired program code and program data in theform of instructions or data structures and that can be accessed by acomputer. Main memory 344 provides a physical address space composed ofaddressable memory locations.

Network interface card (NIC) 330 includes one or more interfaces 332configured to exchange packets using links of an underlying physicalnetwork. Interfaces 332 may include a port interface card having one ormore network ports. NIC 330 may also include an on-card memory to, e.g.,store packet data. Direct memory access transfers between the NIC 330and other devices coupled to bus 342 may read/write from/to the NICmemory.

Memory 344, NIC 330, storage disk 346, and microprocessor 310 mayprovide an operating environment for a software stack that includes anoperating system kernel 314 executing in kernel space. Kernel 314 mayrepresent, for example, a Linux, Berkeley Software Distribution (BSD),another Unix-variant kernel, or a Windows server operating systemkernel, available from Microsoft Corp. In some instances, the operatingsystem may execute a hypervisor and one or more virtual machines managedby hypervisor. Example hypervisors include Kernel-based Virtual Machine(KVM) for the Linux kernel, Xen, ESXi available from VWware, WindowsHyper-V available from Microsoft, and other open-source and proprietaryhypervisors. The term hypervisor can encompass a virtual machine manager(VMM). An operating system that includes kernel 314 provides anexecution environment for one or more processes in user space 345.Kernel 314 includes a physical driver 325 to use the network interfacecard 230.

Computing device 300 may be coupled to a physical network switch fabricthat includes an overlay network that extends switch fabric fromphysical switches to software or “virtual” routers of physical serverscoupled to the switch fabric, such virtual router 220 of FIG. 2.Computing device 300 may use one or more dedicated virtual networks toconfigure minion nodes of a cluster.

API server 320, scheduler 322, controller manager 326, and configurationstore may implement a master node for a cluster and be alternativelyreferred to as “master components.” The cluster may a Kubernetes clusterand the master node a Kubernetes master node, in which case the mastercomponents are Kubernetes master components.

API server 320 includes code executable by microprocessor 310. APIserver 320 may be one or more computer processes. API server 320validates and configures data for objects, such as virtual executionelements (e.g., pods of containers), services, and replicationcontrollers, for instance. A service may be an abstraction that definesa logical set of pods and the policy used to access the pods. The set ofpods implementing a service are selected based on the servicedefinition. A service may be implemented in part as, or otherwiseinclude, a load balancer. API server 320 may implement aRepresentational State Transfer (REST) interface to process RESToperations and provide the frontend to a corresponding cluster's sharedstate stored to configuration store 328. API server 320 may authenticateand authorize requests. API server 320 communicates with othercomponents to instantiate virtual execution elements in the computinginfrastructure 8. API server 320 may represent a Kubernetes API server.

Configuration store 328 is a backing store for all cluster data. Clusterdata may include cluster state and configuration data. Configurationdata may also provide a backend for service discovery and/or provide alocking service. Configuration store 328 may be implemented as a keyvalue store. Configuration store 328 may be a central database ordistributed database. Configuration store 328 may represent an etcdstore. Configuration store 328 may represent a Kubernetes configurationstore.

Scheduler 322 includes code executable by microprocessor 310. Scheduler322 may be one or more computer processes. Scheduler 322 monitors fornewly created or requested virtual execution elements (e.g., pods ofcontainers) and selects a minion node on which the virtual executionelements are to run. Scheduler 322 may select a minion node based onresource requirements, hardware constraints, software constraints,policy constraints, locality, etc. Scheduler 322 may represent aKubernetes scheduler.

In general, API server 320 may invoke the scheduler 322 to schedule avirtual execution element, which may select a minion node and returns anidentifier for the selected minion node to API server 320, which maywrite the identifier to the configuration store 328 in association withthe virtual execution element. API server 320 may invoke theorchestration agent 209 for the selected minion node, which may causethe container engine 208 for the selected minion node to obtain thevirtual execution element from a storage server and create the virtualexecution element on the minion node. The orchestration agent 209 forthe selected minion node may update the status for the virtual executionelement to the API server 320, which persists this new state to theconfiguration store 328. In this way, computing device 300 instantiatesnew virtual execution elements in the computing infrastructure 8.

Controller manager 326 includes code executable by microprocessor 310.Controller manager 326 may be one or more computer processes. Controllermanager 326 may embed the core control loops, monitoring a shared stateof a cluster by obtaining notifications from API Server 320. Controllermanager 326 may attempt to move the state of the cluster toward thedesired state. Example controllers (not shown) managed by the controllermanager 326 may include a replication controller, endpoints controller,namespace controller, and service accounts controller. Controllermanager 326 may perform lifecycle functions such as namespace creationand lifecycle, event garbage collection, terminated pod garbagecollection, cascading-deletion garbage collection, node garbagecollection, etc. Controller manager 326 may represent a KubernetesController Manager for a Kubernetes cluster.

Network controller 324 includes code executable by microprocessor 310.Network controller 324 may include one or more computer processes.Network controller 324 may represent an example instance of networkcontroller 24 of FIG. 1. The network controller 324 may be a logicallycentralized but physically distributed Software Defined Networking (SDN)controller that is responsible for providing the management, control,and analytics functions of a virtualized network. In particular, networkcontroller 324 may be a logically centralized control plane andmanagement plane of the computing infrastructure 8 and orchestratesvRouters for one or more minion nodes.

Network controller 324 may provide cloud networking for a computingarchitecture operating over a network infrastructure. Cloud networkingmay include private clouds for enterprise or service providers,infrastructure as a service (IaaS), and virtual private clouds (VPCs)for cloud service providers (CSPs). The private cloud, VPC, and IaaS usecases may involve a multi-tenant virtualized data centers, such as thatdescribed with respect to FIG. 1. In such cases, multiple tenants in adata center share the same physical resources (physical servers,physical storage, physical network). Each tenant is assigned its ownlogical resources (virtual machines, containers, or other form ofvirtual execution elements; virtual storage; virtual networks). Theselogical resources are isolated from each other, unless specificallyallowed by security policies. The virtual networks in the data centermay also be interconnected to a physical IP VPN or L2 VPN.

Network controller 324 may provide network function virtualization (NFV)to networks, such as business edge networks, broadband subscribermanagement edge networks, and mobile edge networks. NFV involvesorchestration and management of networking functions such as aFirewalls, Intrusion Detection or :Preventions Systems (IDS/IPS), DeepPacket Inspection (DPI), caching, Wide Area Network (WAN) optimization,etc. in virtual machines, containers, or other virtual executionelements instead of on physical hardware appliances. The main driversfor virtualization of the networking services in this market are time tomarket and cost optimization.

Network controller 324 programs network infrastructure elements tocreate virtual networks and may create interface configurations forvirtual network interfaces for the virtual networks.

Additional information regarding network controller 24 operating inconjunction with other devices of data center 10 or othersoftware-defined network is found in International Application NumberPCT/US2013/044378 and in U.S. patent application. Ser. No. 14/226,509,incorporated by reference above.

Network controller manager 325 includes code executable bymicroprocessor 310. Network controller manager 325 may be one or morecomputer processes. Network controller manager 325 operates as aninterface between the orchestration-oriented elements (e.g., scheduler322, API server 320, controller manager 326, and configuration store328) and network controller 324. In general, network controller manager325 monitors the cluster for new objects (e.g., pods and services).Network controller manager 325 may isolate pods in virtual networks andconnect pods with services.

Network controller manager 325 may be executed as a container of themaster node for a cluster. In some cases, using network controllermanager 325 enables disabling the service proxies of minion nodes (e.g.,the Kubernetes kube-proxy) such that all pod connectivity is implementedusing virtual routers, as described herein.

Network controller manager 325 may use the controller framework for theorchestration platform to listen for (or otherwise monitor for) changesin objects that are defined in the APT and to add annotations to some ofthese objects. The annotations may be labels or other identifiersspecifying properties of the objects (e.g., “Virtual Network Green”).Network controller manager 325 may create a network solution for theapplication using an interface to network controller 324 to definenetwork objects such as virtual networks, virtual network interfaces,and access control policies. Network controller 324 may implement thenetwork solution in the computing infrastructure by, e.g., configuringthe one or more virtual network and virtual network interfaces in thevirtual routers.

The following example deployment configuration for this applicationconsists of a pod and the virtual network information for the pod:

apiVersion: v1 kind: Pod metadata:  name: multi-net-pod  annotations: networks: ‘[   { “name”: “red-network” },   { “name”: “blue-network” },  { “name”: “default/extns-network” }  ]’ spec:  containers:  - image:busybox  command:   - sleep   - “3600”  imagePullPolicy: IfNotPresent name: busybox  stdin: true  tty: true  restartPolicy: Always

This metadata information is copied to each pod replica created by thecontroller manager 326. When the network controller manager 325 isnotified of these pods, network controller manager 325 may createvirtual networks as listed in the annotations (“red-network”,“blue-network”, and “default/extns-network” in the above example) andcreate, for each of the virtual networks, a virtual network interfaceper-pod replica (e.g., pod 202A) with a unique private virtual networkaddress from a cluster-wide address block (e.g. 10.0/16) for the virtualnetwork. In accordance with techniques described herein, networkcontroller manager 325 may drive the creation of multiple virtualnetwork interfaces per-pod replica using a single network module 206Afor configuring the pod replica host.

Various components, functional units, and/or modules illustrated inFIGS. 1-3 and/or illustrated or described elsewhere in this disclosuremay perform operations described using software, hardware, firmware, ora mixture of hardware, software, and firmware residing in and/orexecuting at one or more computing devices. For example, a computingdevice may execute one or more of such modules with multiple processorsor multiple devices. A computing device may execute one or more of suchmodules as a virtual machine executing on underlying hardware. One ormore of such modules may execute as one or more services of an operatingsystem or computing platform. One or more of such modules may execute asone or more executable programs at an application layer of a computingplatform. In other examples, functionality provided by a module could beimplemented by a dedicated hardware device. Although certain modules,data stores, components, programs, executables, data items, functionalunits, and/or other items included within one or more storage devicesmay be illustrated separately, one or more of such items could becombined and operate as a single module, component, program, executable,data item, or functional unit. For example, one or more modules or datastores may be combined or partially combined so that they operate orprovide functionality as a single module. Further, one or more modulesmay operate in conjunction with one another so that, for example, onemodule acts as a service or an extension of another module. Also, eachmodule, data store, component, program, executable, data item,functional unit, or other item illustrated within a storage device mayinclude multiple components, sub-components, modules, sub-modules, datastores, and/or other components or modules or data stores notillustrated. Further, each module, data store, component, program,executable, data item, functional unit, or other item illustrated withina storage device may be implemented in various ways. For example, eachmodule, data store, component, program, executable, data item,functional unit, or other item illustrated within a storage device maybe implemented as part of an operating system executed on a computingdevice.

FIG. 4 is a flow diagram illustrating example creation of multiplenetwork virtual interfaces for a virtual execution element using asingle network module, according to techniques described in thisdisclosure. For purposes of example, the operations are described withrespect to components of computing devices 200 and 300 of FIGS. 2-3. APIserver 320 receives a request to instantiate a pod 202A and modifies theconfiguration store 328 by generating and storing configurationinformation for creating the pod 202A (402). Scheduler 322 may selectthe computing device 200 as the host minion node for the pod 202A. APIserver 320 may annotate the pod 202A with a list of multiple virtualnetworks and a uuid for the pod (pod_uuid). Other forms of identifiersfor the pod may be used. The annotations may be labels for the podconfiguration that indicate the virtual networks, such as “virtualnetwork A” and “virtual network B”.

Network controller manager 325 listens for new objects from API server320 and determines that pod 202A is to be instantiated on computingdevice 200 and determines, from the annotations, that the pod 202Arequires virtual network interfaces with the multiple virtual networksindicated in the annotations. The listening may be in response tosubscribing to API server 320 notifications on a RESTful interface, forexample.

Network controller manager 325 directs network controller 324 to createthe virtual networks and to create virtual network interfaces for thepod 202A for the virtual networks (404). Network controller manager 325may annotate the pods with respective uuids for the one or more virtualnetwork interfaces (e.g, vni_uuids) to be created by network controller324 as well as the allocated, respective unique private virtual networkaddresses (and in some cases MAC addresses). Other forms of identifiersfor the virtual network interfaces may be used.

Network controller 324 may associate virtual network interfaces with thepod in interface configuration 25 for the pod 202A. For example, networkcontroller 324 may create a list of virtual network interfaces for thevirtual networks and may associate the vni_uuids with the pod uuid ininterface configuration data 25 for the pod 202A. The vni-uuids may beanother identifier for the virtual network interfaces, such as virtualmachine interface identifiers. Network controller 324 may send theinterface configuration data 25 to the virtual router agent 216 forvirtual router 220 of computing device 200 and configure correspondingvirtual network interfaces 212A, 212B in the computing device 200 (406).Virtual router agent 216 may store an association of each vni_uuid withthe corresponding configured virtual network interface.

To setup the pod 202A, orchestration agent 209 obtains containerspecification data for pod 202A and ensures the containers execute bycomputing device 200 (408). The container specification data may includethe pod uuid for pod 202A. The orchestration agent 209 invokes a singlenetwork plugin 206A to configure the virtual network interfaces for thepod 202A (410). Network plugin 206A requests (412) and obtains theinterface configuration data 25 from virtual router agent 216 (414).Network plugin 206A may obtain the interface configuration data 25 fromvirtual router agent 216 by requesting the interface configuration datafor the pod corresponding to the pod_uuid included in the containerspecification data for pod 202A.

To create each of the virtual network interfaces 212A, 212B indicated ininterface configuration data 25 (416), network plugin 206A may insertthe virtual network interface into the pod 202A network namespace (e.g.,one end of a veth pair that is the virtual network interface) (418) andmay make any necessary changes on the computing device 200 (e attachingthe other end of the veth pair into virtual router 220—this end may havebeen previously attached to another bridge).

Network plugin 206A notifies virtual router agent 216 of thenow-operational (by virtue of insertion into pod 202A) virtual networkinterfaces 212A, 212B (420). Network plugin 206A may also obtain thevirtual network addresses from the virtual router agent 216 (422) or byinvoking an appropriate IPAM plugin. Network plugin 206A may configurethe virtual network addresses inside the pod 202A network namespace andmay setup routes by invoking the virtual router agent 216.Alternatively, network plugin 206A may configure the virtual networkaddresses inside the pod 202A network namespace and may setup routesconsistent with the IP Address Management section by invoking anappropriate IPAM plugin. Network plugin 206A may update theorchestration control plane by notifying orchestration agent 209 (424).

As such, the techniques described a way in which a user can provide alist of networks as an annotation in the pod 202A YAML. The networkcontroller manager 325 may parse this list of networks and create therespective ports in the virtual router 220. When the pod 202A isscheduled on computing device 200, the network plugin 206A may query thevirtual router agent 216 for ports. The virtual router agent 216 willrespond back with a list of ports, and for every member of this list,the network plugin 206A will create the tap interface and attach the tapinterface to pod 202A. Because all of the virtual network interfaces212A, 212B are created in a single call flow, this may provide betterperformance in creating the virtual network interfaces and attachingthem to pods. Containers 229A may communicate via either of virtualnetwork interfaces 212A, 212B to exchange packets with other pods of thecluster on the corresponding networks, or externally to the virtualnetworks and pods of the cluster using, e.g., a gateway.

In some cases, the techniques may enable running different containernetwork functions such as a containerized security device or acontainerized router in a computing infrastructure using anorchestration platform. The container network functions may be such thatordinarily require network interfaces for multiple networks, again, suchas routers, NAT devices, packet analyzer, and firewalls or othersecurity devices. The techniques may therefore enable service chainingwith a container orchestration platform for a container-centriccomputing infrastructure.

For example, any one or more of containers 229A may represent acontainerized network function or containerized network functionvirtualization (NFV) instance. Container 229A of pod 202A has virtualnetwork interface 212A with a first virtual network corresponding to VRF222A and a virtual network interface 212B with a second virtual networkcorresponding to VRF 22213. Other containerized applications executingin pods on computing device 200 or other minion nodes of the cluster andthat have virtual network interfaces in the first virtual network or thesecond virtual network can exchange packets with container 229A and thecontainerized network function. A service chain of one or morecontainedzed network functions may apply a sequence of services tonetwork packets that traverse the service chain. The VRFs 222 of virtualrouters 220 for the minion nodes may be configured to cause trafficforwarding along the sequence of services, such as by configuringservice VRFs for the containerized network functions to use as left VRFsfor the service.

In one example use case, for a two tier application with a frontend anda database backed, the frontend pod can be configured as a virtualnetwork endpoint for virtual network A (corresponding to VRF 222A) andthe database pod can be configured as a virtual network endpoint forvirtual network B (corresponding to VRF 222B). A containerized firewallmay be deployed as the container 229A instance of pod 202A. Virtualnetwork interface 212A is an interface for virtual network A, andvirtual network interface 212B is an interface for virtual network B.Packets received at virtual network interface 212A from the frontend podmay be processed by the containerized firewall and output via virtualnetwork interface 212B over virtual network B to the backend databasepod.

The techniques described herein may be implemented in hardware,software, firmware, or any combination thereof. Various featuresdescribed as modules, units or components may be implemented together inan integrated logic device or separately as discrete but interoperablelogic devices or other hardware devices. In some cases, various featuresof electronic circuitry may be implemented as one or more integratedcircuit devices, such as an integrated circuit chip or chipset.

If implemented in hardware, this disclosure may be directed to anapparatus such as a processor or an integrated circuit device, such asan integrated circuit chip or chipset. Alternatively or additionally, ifimplemented in software or firmware, the techniques may be realized atleast in part by a computer-readable data storage medium comprisinginstructions that, when executed, cause a processor to perform one ormore of the methods described above. For example, the computer-readabledata storage medium may store such instructions for execution by aprocessor.

A computer-readable medium may form part of a computer program product,which may include packaging materials. A computer-readable medium maycomprise a computer data storage medium such as random access memory(RAM), read-only memory (ROM), non-volatile random access memory(NVRAM), electrically erasable programmable read-only memory (EEPROM),Flash memory, magnetic or optical data storage media, and the like. Insome examples, an article of manufacture may comprise one or morecomputer-readable storage media.

In some examples, the computer-readable storage media may comprisenon-transitory media. The term “non-transitory” may indicate that thestorage medium is not embodied in a carrier wave or a propagated signal.In certain examples, a non-transitory storage medium may store data thatcan, over time, change (e.g., in RAM or cache).

The code or instructions may be software and/or firmware executed byprocessing circuitry including one or more processors, such as one ormore digital signal processors (DSPs), general purpose microprocessors,application-specific integrated circuits (ASICs), field-programmablegate arrays (FPGAs), or other equivalent integrated or discrete logiccircuitry. Accordingly, the term “processor,” as used herein may referto any of the foregoing structure or any other structure suitable forimplementation of the techniques described herein. In addition, in someaspects, functionality described in this disclosure may be providedwithin software modules or hardware modules.

What is claimed is:
 1. A computing device comprising: processingcircuitry coupled to a memory device; a network module configured forexecution by the processing circuitry; an orchestration agent configuredfor execution by the processing circuitry, wherein the orchestrationagent is an agent of an orchestrator for a computing infrastructure thatincludes the computing device, wherein the orchestration agent isconfigured to: instantiate a virtual execution element; and invoke thenetwork module, wherein the network module is configured to: obtain anidentifier of a first virtual network interface for a first virtualnetwork and an identifier of second virtual network interface for asecond virtual network; and attach the first virtual network interfaceto the virtual execution element to enable packetized communications bythe virtual execution element on the first virtual network; and attachthe second virtual network interface to the virtual execution element toenable packetized communications by the virtual execution element on thesecond virtual network.
 2. The computing device of claim 1, furthercomprising: a virtual router comprising a first virtual routing andforwarding instance for the first virtual network and a second virtualrouting and forwarding instance for the second virtual network, whereinthe network module is configured to attach the first virtual networkinterface to the first virtual routing and forwarding instance to causethe virtual router to forward packets destined for a virtual networkaddress of the first virtual network interface to the virtual executionelement, and wherein the network module is configured to attach thesecond virtual network interface to the second virtual routing andforwarding instance to cause the virtual router to forward packetsdestined for a virtual network address of the second virtual networkinterface to the virtual execution element.
 3. The computing device ofclaim 2, further comprising: a virtual router agent for the virtualrouter, the virtual router agent configured for execution by theprocessing circuitry, wherein the virtual router agent is configured toreceive the identifier of the first virtual network interface and theidentifier of the second virtual network interface from a networkcontroller for the computing infrastructure, and wherein the virtualrouter agent is configured to provide the identifier of the firstvirtual network interface and the identifier of the second virtualnetwork interface to the network module.
 4. The computing device ofclaim 3, wherein virtual router agent stores the identifier of the firstvirtual network interface and the identifier of the second virtualnetwork interface in association with an identifier for the virtualexecution element, wherein the network module is configured to: receivethe identifier for the virtual execution element from the orchestrationagent; and send, to the virtual router agent, the identifier for thevirtual execution element to request identifiers of virtual networkinterfaces for the virtual execution element; and receive, from thevirtual router agent in response to the request, the identifier of thefirst virtual network interface and the identifier of the second virtualnetwork interface.
 5. The computing device of claim 1, wherein, toattach the first virtual network interface to the virtual executionelement, the network module is configured to insert the first virtualnetwork interface into a network namespace of the virtual executionelement.
 6. The computing device of claim 1, wherein the first virtualnetwork interface comprises a veth pair, and wherein, to attach thefirst virtual network interface to the virtual execution element, thenetwork module is configured to attach one end of the veth pair to thevirtual execution element.
 7. The computing device of claim 1, whereinthe virtual execution element comprises one or more containers.
 8. Thecomputing device of claim 1, wherein the virtual execution elementcomprises a Kubernetes pod and the orchestration agent comprises aKubernetes kuhelet.
 9. A controller comprising one or more computingdevices interconnected by a physical network, wherein each of thecomputing devices comprises processing circuitry coupled to a memorydevice, wherein the controller further comprises: an orchestrator for avirtualized computing infrastructure, wherein the orchestrator isconfigured fur execution by the processing circuitry, wherein theorchestrator is configured to: send, to a network controller, a requestto create, for a virtual execution element to he instantiated in acomputing device of the virtualized computing infrastructure, respectivevirtual network interfaces for a first virtual network and a secondvirtual network; and the network controller, wherein the networkcontroller is configured for execution by the processing circuitry,wherein the network controller is configured to: send, to the computingdevice, interface configuration data to configure a first virtualnetwork interface for the first virtual network and a second virtualnetwork interface for the second virtual network, wherein the interfaceconfiguration data includes an identifier of the first virtual networkinterface for the first virtual network and an identifier of the secondvirtual network interface for the second virtual network.
 10. Thecontroller of claim 9, wherein the network controller is configured to:send, to a virtual router agent for a virtual router of the computingdevice, the identifier of the first virtual network interface for thefirst virtual network and the identifier of the second virtual networkinterface for the second virtual network.
 11. The controller of claim 9,wherein the network controller is configured to: send, to a virtualrouter agent for a virtual router of the computing device, theidentifier of the first virtual network interface for the first virtualnetwork and the identifier of the second virtual network interface forthe second virtual network; send, to the virtual router agent, anassociation of an identifier for the virtual execution element, theidentifier of the first virtual network interface for the first virtualnetwork, and the identifier of the second virtual network interface forthe second virtual network.
 12. The controller of claim 11, wherein theorchestrator is configured to: send, to an orchestration agent of thecomputing device, the identifier for the virtual execution element tocause the orchestration agent to instantiate the virtual executionelement and query, based on the identifier for the virtual executionelement, the virtual router agent for virtual network interfaces for thevirtual execution element.
 13. The controller of claim 9, furthercomprising: a network controller manager for the network controller,wherein the network controller manager is configured for execution bythe processing circuitry, wherein the network controller manager isconfigured to: allocate a virtual network address for the first virtualnetwork interface; allocate a virtual network address for the secondvirtual network interface; direct the network controller to configurethe first virtual network interface with the virtual network address forthe first virtual network interface; and direct the network controllerto configure the second virtual network interface with the virtualnetwork address for the second virtual network interface.
 14. Thecontroller of claim 9, wherein the virtual execution element executes anetwork function, and wherein the orchestrator is further configured to:configure a service chain of one or more virtual execution elements,including the virtual execution element, to cause network packetsreceived at the first virtual network interface to be processed by thenetwork function and output via the second virtual network interface.15. A method comprising: sending, by an orchestrator for a virtualizedcomputing infrastructure to a network controller for the virtualizedcomputing infrastructure, a request to create, for a virtual executionelement to he instantiated in a computing device of the virtualizedcomputing infrastructure, respective virtual network interfaces for afirst virtual network and a second virtual network; and sending, by thenetwork controller to the computing device, interface configuration datato configure a first virtual network interface for the first virtualnetwork and a second virtual network interface for the second virtualnetwork, wherein the interface configuration data includes an identifierof the first virtual network interface for the first virtual network andan identifier of the second virtual network interface for the secondvirtual network.
 16. The method of claim 15, further comprising:instantiating, by the computing device, the virtual execution element;attaching, by a network module, the first virtual network interface tothe virtual execution element to enable packetized communications by thevirtual execution element on the first virtual network; and attaching,by the network module, the second virtual network interface to thevirtual execution element to enable packetized communications by thevirtual execution element on the second virtual network.
 17. The methodof claim 15, wherein the computing device includes a virtual routercomprising a first virtual routing and forwarding instance for the firstvirtual network and a second virtual routing and forwarding instance forthe second virtual network, the method further comprising: attaching, bythe network module, the first virtual network interface to the firstvirtual network interface to the first virtual routing and forwardinginstance to cause the virtual router to forward packets destined for avirtual network address of the first virtual network interface to thevirtual execution element, and attaching, by the network module, thesecond virtual network interface to the second virtual routing andforwarding instance to cause the virtual router to forward packetsdestined for a virtual network address of the second virtual networkinterface to the virtual execution element.
 18. The method of claim 17,wherein the computing device includes irtua router agent for the virtualrouter, the method further comprising: receiving, by the virtual routeragent, the identifier of the first virtual network interface and theidentifier of the second virtual network interface from a networkcontroller for the computing infrastructure; and providing, by thevirtual router agent to the network module, the identifier of the firstvirtual network interface and the identifier of the second virtualnetwork interface.
 19. The method of claim 18, storing, by the virtualrouter agent, the identifier of the first virtual network interface andthe identifier of the second virtual network interface in associationwith an identifier for the virtual execution element, receiving, by thenetwork module, the identifier for the virtual execution element fromthe orchestration agent; sending, by the network module to the virtualrouter agent, the identifier for the virtual execution element torequest identifiers of virtual network interfaces for the virtualexecution element; and receive, by the network module from the virtualrouter agent in response to the request, the identifier of the firstvirtual network interface and the identifier of the second. virtualnetwork interface.
 20. The method of claim 15, wherein the virtualexecution element comprises one or more containers.